The invention relates to a track guidable omnibus of the type such as is known from German Patent No. (DE-PS) 3,013,488 for example. Such omnibus contains a transverse guide roller mounted on a bracket with a preferred breaking point for preventing secondary damage to the vehicle steering in case of collisions.
The preferred breaking point in the bracket of the transverse guide roller is intended to Protect the linkage of the steerable vehicle axle from consequent damage in the case of an accidental collision of the transverse guide roller with road obstacles. Collisions of this type normally occur outside the track-guiding road, that is to say during manually steered service, particularly during shunting or during avoidance maneuvers. A crack or a total breakage of the preferred breaking point is signalled to the driver visually and/or acoustically in his field of perception. The driver has to stop and send for a workshop vehicle, which exchanges the broken transverse guide roller for a transverse guide roller in perfect condition, which is done relatively quickly.
It is impossible to exclude the possibility that a breakage of the preferred breaking point might also occur in track-guided service, that is to say, within the track-guiding road. Because as a result of the automatic track-guidance of the vehicle, the driver no longer has his hands on the steering wheel of the omnibus, and can also simplY direct his attention to other things than steering the vehicle, there is a danger of the vehicle temporarily travelling unguided in the case of a breakage of the preferred breaking point. Violent stressing of the preferred breaking point of the transverse guide roller may occur firstly during the introduction of the vehicle at the start of the track-guided route, or by a lateral road obstacle present within the road, which the transverse guide roller rolls over. Since the transverse guide roller is mounted rigidly in the lateral direction, such an obstacle on the transverse guide rail must almost inevitably lead to a breakage of the transverse guide roller.
An object of the invention is to ensure that, in spite of a breakage of the transverse guide roller during track guided service and when the vehicle driver's attention is elsewhere, the vehicle is nevertheless maintained within the track-guiding transverse guide rails which could Per se be over-rolled by the vehicle wheels.
This object is achieved according to the invention by providing an arrangement wherein an emergency contact surface located approximately at the same height as the transverse guide roller and exposed freely towards the outside of the wheel is fitted to the bracket arm supported at a point located nearer the vehicle wheel -- considered from the preferred breaking point, which surface is, however, set back in the lateral direction relative to the external circumferential part of the transverse guide roller, but which overhangs (dimension a) the external side flank of the wheel tire laterally. By virtue of the emergency contact surface fitted to the bracket arm set back in the lateral direction and relatively low down, in spite of a broken transverse guide roller it is possible for the bracket arm to be maintained on the track at least sufficiently for the tire of the vehicle wheel not to touch the transverse guide rail with its leading circumferential part, so that the danger of the vehicle wheel "climbing up" onto the transverse guide rail is eliminated.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.